Menendez Brothers Attorney Mark Geragos Makes Case for New Trial

Erik and Lyle Menendez have at least 2 new pieces of evidence backing their claim their father was molesting them, and their new high-powered attorney says it's enough for them to get a new trial ... and perhaps a new verdict.

The Menendez brothers' attorney Mark Geragos joined us Thursday on "TMZ Live," explaining why a recently discovered letter written by Erik, as well as the rape claims made by former Menudo member Roy Rossello, are both crucial if they get their day back in court.

He says either piece of evidence -- the letter or Rossello's allegation -- could've resulted in a way different outcome in the 90s. Remember, they were sentenced to life in prison without the possibility of parole.

As we reported, new legal docs filed by Geragos, and obtained by TMZ, reference Rossello's claim he was drugged and raped by the brothers' father, Jose. The petition also points to a letter Erik wrote to a cousin months before they shot their parents in which he says his father was molesting them.

We asked Geragos, hypothetically, if a judge grants the brothers a new trial ... how would he address the fact Erik and Lyle still premeditatively killed not only Jose, but their mother, Kitty, as well. He had a very interesting response.